Why an octuple pom-pom concentrated eight barrels

Why point all eight barrels of an octuple pom-pom at one aircraft?

Concentrated fire could break up the aircraft and make sure it was destroyed at range.

An octuple pom-pom concentrated eight barrels on one aircraft. The purpose was to break up a target and make sure it was destroyed at range. Concentrating the barrels was considered an advantage rather than wasted fire. This was the tactical reasoning offered for the large mount.